Minor refactoring.

Author: And1sS

src/main/java/org/prebid/server/analytics/reporter/pubstack/PubstackAnalyticsReporter.java

@@ -118,9 +118,7 @@ public String name() {
     @Override
     public void initialize(Promise<Void> initializePromise) {
         vertx.setPeriodic(configurationRefreshDelay, id -> fetchRemoteConfig());
-        fetchRemoteConfig()
-                .onSuccess(initializePromise::succeed)
-                .onFailure(initializePromise::fail);
+        fetchRemoteConfig().onComplete(initializePromise);
     }
 
     void shutdown() {